The use of bone screws and plates for stabilization and immobilization of the cervical spine is common. One concern, however, with screws being implanted in the lateral masses of the cervical spine is that there are sensitive and/or important structures adjacent to the masses, which, because of their proximity to the implant, may be damaged by insertion or dislocation of screws. In the cervical spine, the vertebral arteries are positioned laterally beneath the lateral masses and comprise critical structures which should not be compromised. In addition, the facet joints, which provide natural coupling of sequential bones, together should also be avoided if possible. Avoidance of these bodies has been an important and ongoing concern with respect to posterior screw insertion. Current lateral mass screws provide little in the way of reasonable or practical solutions for ensuring proper screw insertion.
Accordingly, there remains a need for improved methods and devices for implanting bone screws in the spinal column, and in particular in the cervical spine.